Automatic Milking System

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Automatic Milking System machines were first developed in the mid-1970s in response to the arduous and costly task of pumping milk from dairy animals on farms. The concept behind the automatic milking system (AMS) is that cows (and in some cases, goats), will voluntarily enter the barn in order to feed, during which time a robotic machine attaches pumps to the teats of the animal and begins pumping. The AMS is employed at regular intervals during the day throughout the cow’s lactation cycle (approximately 300 days per year).

AMS is said to be beneficial not only for removing the physical labor aspect of the task, but also because it is a more humane way to extract milk from animals, subjecting them to little or no discomfort.

Contents

Milking cows, like many tasks on farms, was initially completed by hand. Milking equipment was slow to develop, and when it did, it was heavily criticized and associated with imperfections.

While there were many attempts at producing a machine capable extracting milk, nothing made a mark until the 1860s. In 1862, an American by the name of Colvin invented a hand-held vacuum that extracted milk via suction. It consisted of four rubber-teat cups that were attached to the teats of the animal. Milk was sucked out by the vacuum and deposited into a pail. This machine extracted milk from the animal in an instantaneous fashion, causing undue harm to the animal. Milk production resulted in blood drops in the milk. A Birmingham-based firm purchased the patent but nothing further derived from it. Seeing it as cruel, dairy and farming societies sought out more humane procedures by offering prize money.[1]

Other milking machines appeared in 1865 and 1870, and they claimed to be able to fill a 3.5-gallon (13.25-L) pail within seven minutes. According to the advertisement for the milking machines:

“the milk gathers no impurities, as in the usual handling of the teats and udder, in which numerous scales of skin, hairs, and other cow-flavored matter fall into the milk pail. The relief from the exertion of the wrists and arms is very welcome to the milker.”[2]

New Yorker William Cozier introduced a milking machine to the public in 1877. Claiming it had been in existence for years, this machine had four narrow metal probes that were inserted into the animal’s teats, to which were attached silver tubes that connected to large rubber hoses. The milk would be extracted, traveling through the tubes into the hose, before making its final stop in a pail. This type of milking machine, unlike ones to come, did not operate via suction, but used gravity flow to produce milk. A hand-held vacuum pump and a jar were added to modify the gravity flow instrument.

Milking continued to raise criticism for the harm it could impose on the animal. The editor of American Agriculture had noted that many milking methods had resulted in drops of blood in the milk produced from excessive suctioning in an 1878 edition of the publication.

Attempting to avoid the suction route, other machines were developed. In the 1881, the Crees Lactator was the first one of many lactators to arrive on the scene. It retrieved milk by gripping the teats of the cow by two sets of rollers that were rotated by a belt. As the belt rotated, the rollers gently squeezed and massaged the teats to extract milk into a pail. Most lactators of this time were considered unhygienic.

Further improvements were made when the Mehring foot-powered milker hit the market in 1891. The Mehring milker was shaped like a rowing machine and was capable of milking two cows at once, somewhat decreasing the work of dairy farmers.

William Murchland, a Scot, introduced several vacuum pump machines throughout his lifetime, all of which were patented and put to use on farms. His first machine was permanently installed and extracted milk with a water-vacuum system. Again, this system was successful but still caused harm to the animals.

In 1895, Dr. Alexander Shields of Glasgow invented a thistle milking machine that produced milk by pulsating. It was less stressful to the cows because it produced a tiny, brief puncture mark in the teat, which was less painful than the constant sucking of the vacuum pump. While his machine garnered some success, it was criticized for being too expensive and complicated, and for consisting of a pump that was far too large for the operation. While it was criticized at the time, the pulsating factor played a large role in the evolution of successful milking machines. The U.S. Dairy Association approved of it, despite criticism, three years after it was invented. At that time, many manufacturers began marketing pulsating milking machines.[3]

In the next couple decades, milking machines improved very little. This may have been due to the idea that technology and milking did not go hand in hand. One critic, S.M. Babcock, the inventor of the Babcock butter test, said in the National Dairyman, “milking machines would result in poorer quality of milk and lowering the standards of dairy animals.”[4]

The next invention did not roll out until 1916. The first attempt to reduce the labor and costs of milking tasks came with the production of vacuum pump milking, utilizing single cylinder gas engines. These were used until the 1930s when electricity replaced gas as the power source. One of the main complaints of this time involved the copper, aluminum, and brass pails that were used to collect the milk; they often added an undesirable flavor to the milk. Other sanitation issues arose with the pipes and tubes used to transport the milk. Due to the difficulty in cleaning these machines, hygiene was a huge concern.

Manufacturers began to see a market for developing milking machines. One company to result from this was the Pine Tree Milking Machine Co., formed by the Babson brothers. The Pine Tree Milking Machine, the first model the brothers constructed, was an overall milking machine fitted with a pulsator that sat in an upright position. It was the highest performing pulsator of its time, and its easy operation made it the top choice for farmers of the 1920s.

The Surge Bucket Milker was also introduced in the 1920s. In 1922, Herbert McCornack constructed his invention using the family’s oven roasting pan to form the basis of his machine. Using a leather strap that was hoisted over the cow’s back, spring steel rods were suspended while a tug-and-pull movement was employed on the cow’s teats. This machine was more satisfactory because it was cleaner and more sanitary than previous machines. It saved farmers a lot of money because they did not have to dispose of the poor quality milk that would occasionally result from the other machines. One of the major drawbacks, however, was that the rubber teats would fall off. Surge Milkers continued to be built until 1999.[5]

After the Second World War, there was a significant priority for humane and comforting techniques to be practiced during the milking process. A brochure composed by International Harvester is evidence of this: “Milkers have eliminated the hand milking chore on many American farms. Modern milking machines extract the milk from cows’ udders with a gentle massaging action.”[6]

The idea of automatic milking first arose in the 1970s when farmers and manufacturers realized the heavy costs associated with milking prior to AMS. The first step in the direction towards AMS was the introduction of concentrate feeders, as well as milking parlors and automatic cluster removers, all of which played a significant part in developing a system of identification for cows, a crucial factor for AMS. Concentrate feeders were houses that the cows could enter at any time. During this time, automatic clusters would be attached to the teats by hand and the process of milking the cow would begin.

This was not a perfect process by any means and there were a great deal of modifications made to improve the automatic clusters during the 1980s and '90s. It took just under 10 years for manufacturers to find a way to make the clusters locate and catch onto the teats and become fully integrated automatic milkers.

Milking parlors evolved to include machinery that recorded milk yield and machines that would monitor and detect the health of the cows’ udders. The different types of machines developed at this time were beneficial in drastically reducing the labor and time spent on the cows; thus the idea to remove physical labor entirely was presented.

The first milking robots appeared on commercial dairy farms in the Netherlands in 1992 and spread throughout the world by the end of the 1990s. More than 1,100 farms were using the automatic milking process by the close of 2001. Most farms and dairy plants in Europe were already using the AM system. It became widespread in Europe more so than the U.S. because of the price of labor but also because Europe was the first continent to test out the system and most of the components of the robotic machinery were Dutch-made. However, AMS has hit the U.S. and it continues to grow as a primary milking method.[7]

The salient feature of AMS is that it draws cows to the parlor for voluntary milking, a concept never before devised. With the cows associating it with feeding, they regularly proceed into the parlor for feedings at several intervals during the day, at which point the AMS clusters attach themselves to the cows' teats and begin extracting milk with rollers that massage the teats and roll out milk. This farming technique has never been attempted before.

Different techniques have been used to train the cows to go into the parlor. Some studies in New Zealand have revealed that providing the cows with drinking water inside the parlor entices them to leave their grazing area. It also suggests that cows can be trained by providing a patch of fresh pasture on the side of the parlor, which motivates the cows to leave the parlor quickly once they have finished feeding and the milking has ceased. Once cows get into the routine of learning where and how to access the feeding box, other cows and calves can learn by example. Cows are typically milked an average of two to three times per day.

Furthermore, to completely remove manual labor from the process, some AMS machines include automatic clusters removers. There is also machinery that sprays and cleans the teats of the cow to ensure good hygiene. The machines undergo extensive cleaning and dirt removal to ensure the best quality for the cow, the machine, and the milk itself.

Not only does the AMS minimize the labor required from farmers and other dairy workers, but it means better regulation of the cows, more frequent milking sessions, and less stress for the farmer and the cow.

In terms of the cow’s health, this method is considerably more humane than previous methods. Studies carried out in various countries revealed some deterioration in the somatic cell count, total bacterial count, freezing point depression, and free fatty acids level in the first months when AMS was introduced to a dairy herd. Although this is a less than desirable scenario, the situation gradually improved once the cows adjusted to the new system of milking. The response of the cows, as well, has been positive. After the AMS is introduced to the animals, they become quieter and appear to be calm and not frightened of the machines.

As with every machine, imperfections and faults are sure to be found. The automatic milking system requires farmers to be considerably more fluent in the use and maintenance of technology. This establishes a distance between the cows and the farmers, a concept that may have some effect on farmers quickly detecting diseases and other illnesses in their herd. While the majority of cows seem calm during the milking process, it does mean that some of the more aggressive cows will get to feed and be milked more frequently than others, causing a stressful environment for these animals. Lastly, there are some associated costs with a system this complex that not all farmers may benefit from.[8]